It is not about you.
Your product, your story, your solution.
It is about how, those interested enough to listen, identify with you.
Therefore, a self-serving message is undesirable. Self-serving does not establish trust.
Self-serving is going for the hard close to early in the sales process. It is the easy road. It is wearing a customer down. They say yes just so you go away.
Self-serving is providing information only to talk about your product. Showing you do not understand your product is one tool in a larger tool bag.
A non self-serving sales professional provides solutions to a customers business, that may not be directly associated with their product.
For example: when a clients main concern is growing their business, you need to discuss how to grow their business. Inserting your product along the way is how you are successful. Trust is built through helping them build their business. After all, you listened to their biggest problem.
A non self-serving marketer understands their customers world. Makes a point to become an expert resource in areas related to their problems. When they have a question, they ask you first.
In both examples, the use of your product is the result of understanding the customer and building trust. Trust is built over time, through value provided. It is the long game.
In a world sensitive to sales and marketing messages, it is not enough to be self-serving. Do not sell yourself short by taking the easy road.
Good luck and good selling!